1. Field
The present disclosure relates generally to manufacturing and, in particular, to manufacturing parts. Still more particularly, the present disclosure relates to a method and apparatus for identifying a volume for a feature pattern used for a part.
2. Background
American, Canadian, German, and International Organization for Standardization (ISO) standards may define methods and requirements for specifying multiple levels of feature-related tolerances. However, the manufacturing industry may not have an efficient or effective way of determining whether these requirements are achieved. Furthermore, no means for accurately assessing the effects of computer simulations with respect to feature-related tolerances may be present for features of more than one design size.
In manufacturing products such as aircraft, numerous parts may be assembled and attached to each other to form an aircraft. For example, without limitation, the airframe of an aircraft may involve matching up feature patterns, such as hole patterns, between various mating parts.
In designing these parts and hole patterns, it may be desirable to ensure that when assembled, fasteners can be placed through the holes or pins in one part and those holes and pins may match up with holes in another part. Some variance may be present in the location and size of holes. An acceptable level of variation of the location and size of the holes according to a particular standard may be known as a tolerance. For example, variation between the size of holes and the location of holes may be analyzed to determine whether parts can be properly assembled.
Data from manufactured parts and data from simulations of parts are currently evaluated to identify an amount of float. This float indicates movement that may occur for one or more parts. This movement may be in terms of translation and rotation.
These evaluations may be made with respect to different parameters for the holes. These parameters may include size, location, form, orientation, and other parameters about the holes.
Software may be used to analyze variation with respect to these and other parameters. Currently available software analysis systems, however, only provide an analysis of a hole pattern in two dimensions. In other words, the identification of the float for the movement of a part using a particular hole pattern is only with respect to movement on two dimensions such as a plane. The movement may be translation and rotation on a plane.
Other types of translation in other dimensions other than the two dimensions are not taken into account with currently used software analysis systems for hole patterns. The availability of information only in two dimensions rather than three dimensions may not provide as much information that may be desired for designing hole patterns and assembly processes for parts using the hole patterns. This lack of information may increase the time and effort needed to manufacture an aircraft.
In particular, currently used software analysis systems are designed to provide information about float in which translation may occur on two axes. In other words, the translation occurs on a plane. Further, the currently available software takes into account rotation about one axis. In other words, the rotation is rotation on the plane.
The currently used software analysis systems are unable to provide information in three dimensions with six decrees of freedom with respect to the float. In other words, currently used software analysis systems do not provide information about translation on three axes and do not provide information about rotation on three axes.
This type of potential movement between parts, however, is the actual movement that may occur when parts are assembled. Not having this type of information may result in designs of parts and instructions for operations to assemble parts that may not be as efficient as desired. This inefficiency may increase the time and cost to manufacture a product as the number of parts in a product increases.
For example, manufacturing an aircraft may involve tens of thousands or hundreds of thousands of parts that are put together and connected to each other using fasteners. If the assembly process is not as efficient as desired the amount of time needed to assemble an aircraft may increase greatly. The increases in time results in increased costs and longer than desired manufacturing times for the aircraft.
Further, when parts are more difficult to assemble, more operators, more tools, or both may be needed to position, hold, or position and hold the parts for assembly. With the need for more tools, the expense to acquire and maintain these tools also increases. As a result, manufacturing the aircraft may be more complex, difficult and expensive than desired using currently available software analysis systems for hole patterns.
Therefore, it would be desirable to have a method and apparatus that takes into account at least some of the issues discussed above, as well as other possible issues.